Sealing the future of immersed tunnels - Trelleborg's role in transformative infrastructure projects
Date: 11.06.25
Every day, infrastructure projects around the globe support over $90 trillion in economic activity and connect billions of people. At the heart of these vital networks, the demand for resilient, long-lasting infrastructure solutions continues to grow, and no projects demonstrate this more clearly than those in China’s Greater Bay Area.
The Hong Kong-Zhuhai-Macao Bridge and the ShenZhong Link – two of the world’s most ambitious cross-sea infrastructure projects – are not just redefining regional connectivity; they're driving economic growth and setting new standards for sustainable infrastructure. And, with over 100 years of expertise in immersed tunnel sealing technology, Trelleborg Marine & Infrastructure plays a critical role in ensuring the long-term durability and sustainability of these landmark projects. Through our advanced tunnel sealing systems, we safeguard infrastructure against harsh environmental conditions while supporting future-proof development.
Hong Kong-Zhuhai-Macao Bridge
Spanning nearly 55 kilometers, the Hong Kong-Zhuhai-Macao Bridge is one of the world’s longest cross-sea transportation systems, linking three key economic hubs in southern China. Central to its success is a 6-kilometre immersed tunnel, built to withstand deep-water construction challenges, high-pressure environments, and heavy maritime traffic.
To ensure watertight integrity and durability, Trelleborg supplied Gina Gaskets for the immersion joints, which provide the primary seal between tunnel sections and are designed to endure immense hydrostatic pressure, and Omega seals, which serve as a secondary safeguard, absorbing structural movements caused by soil settlement, tidal forces, and seismic activity. Additional internal rubber waterstops reinforce water resistance and structural longevity for the segment joints.
Given the seismic risks in the region, these sealing systems were engineered to accommodate ground shifts and thermal expansion, ensuring long-term reliability even under extreme conditions. With a lifespan of up to 120 years, they minimize maintenance needs, reduce operational costs, and long-term environmental impact. As global infrastructure faces increasing pressure from rising sea levels and severe weather events, the need for high-quality, long-lasting solutions has never been greater.
ShenZhong Link
The ShenZhong Link is another record-breaking infrastructure project connecting Shenzhen, Zhongshan, and the Nansha District of Guangzhou. Spanning 24 kilometers, this cross-sea passage features the world’s widest immersed tunnel accommodating eight lanes of traffic, man-made islands, and multiple bridge structures, cutting travel time between Zhongshan and Shenzhen from two hours to just 30 minutes.
Trelleborg’s contributions to this project demonstrate our expertise in delivering customized, high-performance sealing solutions for large-scale, complex projects. The company supplied M-Seals, the largest retractable waterstop of its kind globally, engineered and manufactured at Trelleborg’s Qingdao facility to accommodate significant movements in the tunnel structure. Gina and Omega seals were also provided to ensure watertight integrity between the tunnel sections, safeguarding the structure against external water pressure, settlement movements, and temperature variations. Inflatable seals were tailored for critical connection points, enhancing ease of installation and long-term performance.
With over 4,000 ships passing through the Lingdingyang Bay daily and winds reaching up to 88 meters per second, the tunnel was designed to withstand extreme marine conditions while offering a low-carbon alternative to traditional bridges. By enabling more direct routes and integrating rail transport, immersed tunnels reduce congestion, cut emissions, and promote efficient transportation networks - key elements of sustainable infrastructure development.
Advancing tunnel sealing technology
As tunnels are built deeper, wider, and more climate-resilient, sealing technology must evolve in parallel. Trelleborg is at the forefront of advancing material composition, durability, and pressure resilience to meet these growing demands.
For example, dynamic compression testing of Gina seals under simulated seismic effects ensures consistent long-term performance, while advanced burst testing for Omega seals enhances water pressure resistance - critical for deeper tunnels with larger joint openings.
Trelleborg’s innovations extend beyond China. The Fehmarnbelt Tunnel, linking Denmark and Germany, is a pioneering example of new construction methods. By eliminating the traditional steel end-frame, Trelleborg developed an innovative cast-in-place Gina seal solution. This approach reduces corrosion risks, enhances structural efficiency, and speeds up construction.
For Mexico’s Coatzacoalcos Tunnel, seismic risks required extra-large Gina and Omega seals designed to withstand ground accelerations up to 3.5 m/s². Specialized folding and transport techniques allowed for seamless installation, setting new standards in tunnel sealing technology.
Other projects include the Öresund Bridge and immersed tunnel, connecting Sweden and Denmark since 2000. The tunnel, composed of 20 pre-cast concrete elements weighting 55,000 tons each, features Trelleborg’s custom Gina gaskets and on-site vulcanized waterstops designed to address logistical challenges.
Sustainable solutions
Trelleborg’s approach to infrastructure goes beyond delivering industry-leading sealing solutions - it is about engineering sustainability at every stage, from design and manufacturing to installation and lifecycle management.
By optimizing Gina seal manufacturing, we have reduced rubber waste by 13.7 tons annually, reinforcing circular economy principles without compromising performance. Our commitment to recyclable alternatives further enhances material efficiency, reducing reliance on non-renewable resources while maintaining the structural integrity of immersed tunnels.
Our advancements in high-performance elastomers, smart sealing technology, and lifecycle optimization align with EUDR regulations as well as global decarbonization efforts, reducing environmental impact while enhancing long-term resilience. From low-carbon transport solutions to optimized tunnel designs capable of withstanding increasingly destructive weather and instability, Trelleborg’s technology is helping to future-proof urban infrastructure against climate change.
A legacy of reliability, a future of possibilities
Having supplied sealing solutions for nearly 60 immersed tunnels worldwide, Trelleborg continues to set industry benchmarks in infrastructure protection. As global infrastructure projects grow in complexity, Trelleborg remains at the forefront, delivering tailored, high-performance technology that ensures the safety, efficiency, and longevity of critical transport links.
The Hong Kong-Zhuhai-Macao Bridge and ShenZhong Link stand as testaments to Trelleborg’s expertise, demonstrating how innovation in infrastructure can enhance regional connectivity, support economic growth, and promote sustainability.
As new opportunities emerge, Trelleborg Marine & Infrastructure remains committed to delivering reliable, future-ready solutions that meet the evolving needs of global transport networks while driving long-term environmental and operational benefits.
The Hong Kong-Zhuhai-Macao Bridge and the ShenZhong Link – two of the world’s most ambitious cross-sea infrastructure projects – are not just redefining regional connectivity; they're driving economic growth and setting new standards for sustainable infrastructure. And, with over 100 years of expertise in immersed tunnel sealing technology, Trelleborg Marine & Infrastructure plays a critical role in ensuring the long-term durability and sustainability of these landmark projects. Through our advanced tunnel sealing systems, we safeguard infrastructure against harsh environmental conditions while supporting future-proof development.
Hong Kong-Zhuhai-Macao Bridge
Spanning nearly 55 kilometers, the Hong Kong-Zhuhai-Macao Bridge is one of the world’s longest cross-sea transportation systems, linking three key economic hubs in southern China. Central to its success is a 6-kilometre immersed tunnel, built to withstand deep-water construction challenges, high-pressure environments, and heavy maritime traffic.
To ensure watertight integrity and durability, Trelleborg supplied Gina Gaskets for the immersion joints, which provide the primary seal between tunnel sections and are designed to endure immense hydrostatic pressure, and Omega seals, which serve as a secondary safeguard, absorbing structural movements caused by soil settlement, tidal forces, and seismic activity. Additional internal rubber waterstops reinforce water resistance and structural longevity for the segment joints.
Given the seismic risks in the region, these sealing systems were engineered to accommodate ground shifts and thermal expansion, ensuring long-term reliability even under extreme conditions. With a lifespan of up to 120 years, they minimize maintenance needs, reduce operational costs, and long-term environmental impact. As global infrastructure faces increasing pressure from rising sea levels and severe weather events, the need for high-quality, long-lasting solutions has never been greater.
ShenZhong Link
The ShenZhong Link is another record-breaking infrastructure project connecting Shenzhen, Zhongshan, and the Nansha District of Guangzhou. Spanning 24 kilometers, this cross-sea passage features the world’s widest immersed tunnel accommodating eight lanes of traffic, man-made islands, and multiple bridge structures, cutting travel time between Zhongshan and Shenzhen from two hours to just 30 minutes.
Trelleborg’s contributions to this project demonstrate our expertise in delivering customized, high-performance sealing solutions for large-scale, complex projects. The company supplied M-Seals, the largest retractable waterstop of its kind globally, engineered and manufactured at Trelleborg’s Qingdao facility to accommodate significant movements in the tunnel structure. Gina and Omega seals were also provided to ensure watertight integrity between the tunnel sections, safeguarding the structure against external water pressure, settlement movements, and temperature variations. Inflatable seals were tailored for critical connection points, enhancing ease of installation and long-term performance.
With over 4,000 ships passing through the Lingdingyang Bay daily and winds reaching up to 88 meters per second, the tunnel was designed to withstand extreme marine conditions while offering a low-carbon alternative to traditional bridges. By enabling more direct routes and integrating rail transport, immersed tunnels reduce congestion, cut emissions, and promote efficient transportation networks - key elements of sustainable infrastructure development.
Advancing tunnel sealing technology
As tunnels are built deeper, wider, and more climate-resilient, sealing technology must evolve in parallel. Trelleborg is at the forefront of advancing material composition, durability, and pressure resilience to meet these growing demands.
For example, dynamic compression testing of Gina seals under simulated seismic effects ensures consistent long-term performance, while advanced burst testing for Omega seals enhances water pressure resistance - critical for deeper tunnels with larger joint openings.
Trelleborg’s innovations extend beyond China. The Fehmarnbelt Tunnel, linking Denmark and Germany, is a pioneering example of new construction methods. By eliminating the traditional steel end-frame, Trelleborg developed an innovative cast-in-place Gina seal solution. This approach reduces corrosion risks, enhances structural efficiency, and speeds up construction.
For Mexico’s Coatzacoalcos Tunnel, seismic risks required extra-large Gina and Omega seals designed to withstand ground accelerations up to 3.5 m/s². Specialized folding and transport techniques allowed for seamless installation, setting new standards in tunnel sealing technology.
Other projects include the Öresund Bridge and immersed tunnel, connecting Sweden and Denmark since 2000. The tunnel, composed of 20 pre-cast concrete elements weighting 55,000 tons each, features Trelleborg’s custom Gina gaskets and on-site vulcanized waterstops designed to address logistical challenges.
Sustainable solutions
Trelleborg’s approach to infrastructure goes beyond delivering industry-leading sealing solutions - it is about engineering sustainability at every stage, from design and manufacturing to installation and lifecycle management.
By optimizing Gina seal manufacturing, we have reduced rubber waste by 13.7 tons annually, reinforcing circular economy principles without compromising performance. Our commitment to recyclable alternatives further enhances material efficiency, reducing reliance on non-renewable resources while maintaining the structural integrity of immersed tunnels.
Our advancements in high-performance elastomers, smart sealing technology, and lifecycle optimization align with EUDR regulations as well as global decarbonization efforts, reducing environmental impact while enhancing long-term resilience. From low-carbon transport solutions to optimized tunnel designs capable of withstanding increasingly destructive weather and instability, Trelleborg’s technology is helping to future-proof urban infrastructure against climate change.
A legacy of reliability, a future of possibilities
Having supplied sealing solutions for nearly 60 immersed tunnels worldwide, Trelleborg continues to set industry benchmarks in infrastructure protection. As global infrastructure projects grow in complexity, Trelleborg remains at the forefront, delivering tailored, high-performance technology that ensures the safety, efficiency, and longevity of critical transport links.
The Hong Kong-Zhuhai-Macao Bridge and ShenZhong Link stand as testaments to Trelleborg’s expertise, demonstrating how innovation in infrastructure can enhance regional connectivity, support economic growth, and promote sustainability.
As new opportunities emerge, Trelleborg Marine & Infrastructure remains committed to delivering reliable, future-ready solutions that meet the evolving needs of global transport networks while driving long-term environmental and operational benefits.